U.S. patent number 5,595,238 [Application Number 08/307,134] was granted by the patent office on 1997-01-21 for rotatably supported regenerative fluid treatment wheel assemblies.
This patent grant is currently assigned to Engelhard/ICC. Invention is credited to James A. Heywood, Henry Y. Mark.
United States Patent |
5,595,238 |
Mark , et al. |
January 21, 1997 |
Rotatably supported regenerative fluid treatment wheel
assemblies
Abstract
Rotatably supported, regenerative fluid treatment wheel
assemblies include a wheel with circumferential rim and track, a
housing in which the wheel is disposed and a plurality of rollers
disposed within the housing in rolling engagement with the track to
locate a wheel axially and radially within the housing. Seal
flanges are provided projecting radially outwardly from the rim and
are opposed by flexible seals which are clip mounted to walls of
the housing surrounding openings through those walls which are
aligned with the wheel. At least one wheel is preferably spring
loaded so to compensate for any eccentricity in the wheel. The
wheel is belt driven. A subassembly, including a mounting plate,
flange-mounted motor, drive pulley and spring loaded idler pulley
is provided for easy installation and removal. Wear strips
appropriate for contact with either the seal flanges or face of the
wheel core are applied to the flexible seals by pressure sensitive
adhesive. Roller support and location can be applied to hub and
spoke wheels as well. Rollers support and location permits the use
of a smaller hub and a single bearing, thereby minimizing the
center area of the core lost to fluid treatment.
Inventors: |
Mark; Henry Y. (Philadelphia,
PA), Heywood; James A. (Yardley, PA) |
Assignee: |
Engelhard/ICC (Philadelphia,
PA)
|
Family
ID: |
23188387 |
Appl.
No.: |
08/307,134 |
Filed: |
September 16, 1994 |
Current U.S.
Class: |
165/9; 165/8 |
Current CPC
Class: |
B01D
53/06 (20130101); F24F 3/1423 (20130101); B01D
53/261 (20130101); B01D 2253/3425 (20130101); B01D
2257/70 (20130101); B01D 2257/80 (20130101); B01D
2259/4009 (20130101); B01D 2259/4508 (20130101); F24F
2003/1464 (20130101); F24F 2203/1004 (20130101); F24F
2203/1012 (20130101); F24F 2203/1032 (20130101); F24F
2203/104 (20130101); F24F 2203/1048 (20130101); F24F
2203/106 (20130101); F24F 2203/1072 (20130101); F24F
2203/108 (20130101); F24F 2203/1084 (20130101); F24F
2203/1096 (20130101) |
Current International
Class: |
B01D
53/06 (20060101); F23L 015/02 () |
Field of
Search: |
;62/271 ;165/9,8
;277/166,189,223,229 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
0084090 |
|
May 1984 |
|
JP |
|
763385 |
|
Dec 1956 |
|
GB |
|
863901 |
|
Mar 1961 |
|
GB |
|
2064084 |
|
May 1981 |
|
GB |
|
Other References
Kays, W. M.; London, A. L. Compact Heat Exchangers, 3rd.,
McGraw-Hill Book Company, 1984, pp. 186-188, 279..
|
Primary Examiner: Rivell; John
Assistant Examiner: Atkinson; Christopher
Attorney, Agent or Firm: Panitch, Schwarze, Jacobs &
Nadel, P.C.
Claims
What is claimed is:
1. The assembly of claim 3 wherein the pair of seal flanges are
integral with the rim.
2. The assembly of claim 5 wherein the housing includes a pair of
opposing outer walls with openings there-through at least generally
axially aligned with the core of the treatment wheel and further
comprising flexible seals mounted on the housing surrounding each
opening and positioned to contact the seal flanges of the treatment
wheel.
3. A rotatably supported regenerative fluid treatment wheel
assembly comprising:
a regenerative fluid treatment wheel having a core porous in an
axial direction and a circular rim surrounding and secured with the
core;
a track on the treatment wheel encircling the treatment wheel;
a housing surrounding the treatment wheel;
a plurality of rollers disposed within the housing in rolling
engagement with the track; and
a pair of seal flanges extending at least generally radially from
the treatment wheel around the circumference of the treatment wheel
proximal each of two major opposing axial faces of the air
treatment wheel;
wherein the housing includes a pair of opposing outer walls with
openings there- through at least generally axially aligned with the
core of the treatment wheel and further comprising flexible seals
mounted on the housing surrounding each opening and positioned to
contact the seal flanges of the treatment wheel; and
wherein each of the seals is releasably clipped to an edge of one
of the pair of opposing outer walls defining one of the
openings.
4. The assembly of claim 3 further comprising an abrasion resistant
layer adhered to one of the flexible seals at a location directly
opposite and facing the proximal seal flange of the treatment
wheel.
5. A rotatably supported regenerative fluid treatment wheel
assembly comprising:
a regenerative fluid treatment wheel having a core porous in an
axial direction and a circular rim surrounding and secured with the
core;
a track on the treatment wheel encircling the treatment wheel;
a housing surrounding the treatment wheel;
a plurality of rollers disposed within the housing in rolling
engagement with the track; and
a pair of seal flanges extending at least generally radially from
the treatment wheel around the circumference of the treatment wheel
proximal each of two major opposing axial faces of the air
treatment wheel, wherein at least a portion of each seal flange
distal to the core tapers generally axially inwardly as the seal
flange extends away from the core.
6. A rotatably supported regenerative fluid treatment wheel
assembly comprising:
a regenerative fluid treatment wheel having a core porous in an
axial direction;
a pair of seal flanges extending at least generally outwardly from
the treatment wheel around the outer circumference of the treatment
wheel proximal each of two major opposing axial sides of the
wheel;
a housing surrounding the treatment wheel, the housing including a
pair of opposing outer walls with openings therethrough, at least
generally axially aligned with the core of the treatment wheel;
and
flexible seals releasably clipped on the housing surrounding each
opening, each seal positioned to contact one of the seal flanges of
the treatment wheel.
7. The assembly of claim 3 wherein the track, seal flanges and rim
are formed by portions of a one-piece extrusion.
8. The assembly of claim 4 wherein the abrasion resistant layer is
a flexible tape adhered to the one of the flexible seals.
9. The assembly of claim 3 wherein each of the seals includes a
resiliently flexible clip portion having an open channel receiving
and releasably engaging with the edge of one of the walls.
10. The assembly of claim 5 wherein the pair of seal flanges are
integral with the rim.
11. The assembly of claim 6 wherein the pair of seal flanges are
integral with a circular rim surrounding and secured with the
core.
12. The assembly of claim 6 further comprising an abrasion
resistant layer adhered to one of the flexible seals at a location
directly opposite and facing the proximal seal flange of the
treatment wheel contacted by the one flexible seal.
13. The assembly of claim 6 wherein at least a portion of each seal
flange distal to the core tapers generally axially inwardly as the
seal flange extends away from the core.
Description
FIELD OF THE INVENTION
The present invention relates to regenerative fluid treatment
wheels and to assemblies rotatably supporting such wheels.
BACKGROUND OF THE INVENTION
Regenerative type periodic flow devices are conventionally employed
to expose fluid streams to constituents or to transfer heat or
constituents from one fluid stream to another, and thereby from one
area or zone in space to another. Such device might be used to
achieve one of heat transfer, mass transfer, catalysis, ion
exchange, separation of the fluid media, removal of organic
compounds from the fluid media, dilution or concentration of fluid
components, treatment of fluid-carrying organisms, and the capture
and retention of hazardous materials. Typically, these devices are
in the form of a "wheel". The direct contact of the stream to the
constituents or the transfer of heat or constituents from one fluid
stream to another is then accomplished as the wheel rotates.
The one common type of wheel is around a cylindrical hub and
applying commonly constructed by wrapping a corrugated material
around a cylindrical hub and applying a rim around the wrapped
core. The wrapped core is further held in place by extending spokes
radially through the core between the hub and the rim.
Wheels of such construction are used in cycle air-conditioners,
which are known in the art and are based primarily on the Munters
Environmental Control system (MEC) unit as described in U.S. Pat.
No. 2,926,502. As set forth in this patent, the basic open-cycle
air-conditioner operates by dehumidification and subsequent cooling
of air wherein moist hot air is conditioned by basically a
multi-stage process to produce cool air.
In open-cycle air-conditioning systems, a basic multistep approach
is used. This is shown, for example, in Coellner et al. U.S. Pat.
No. 4,594,860. In the inlet path, outside air is subjected to
removal of moisture through a moisture transfer wheel, with the
dried air being cooled by means of a heat exchanger wheel with the
subsequent addition of moisture by an evaporative element so as to
further cool the air before it enters the area to be conditioned.
In the return cycle, the air passes through an exhaust path which
includes a further evaporative element, the heat exchanger wheel, a
heating element, and the moisture transfer wheel, after which the
air is exhausted to the atmosphere. In the return cycle, also
called the outlet path, air passing through the moisture transfer
wheel accomplishes the regeneration of the wheel by driving
moisture therefrom.
The mechanical subsystems which envelop the core section of each
wheel are extremely critical to the operation and longevity of the
assembly, particularly the core. The factors important to the core
include: (1) the mechanical system used to effectively seal one
fluid stream from another, (2) alignment of the core with respect
to the mechanical sealing system, (3) the means used to maintain
the structural integrity of the wheel including the core, (4) the
means used to support and rotate the wheel, and (5) the means by
which the various subsystems are combined to house the core in a
modular assembly, typically referred to as a "cassette".
SUMMARY OF THE INVENTION
In one aspect, the invention is a rotatably supported regenerative
fluid treatment wheel assembly comprising: a regenerative fluid
treatment wheel having a core porous in an axial direction and a
circular rim surrounding and secured with the core; a track on the
treatment wheel encircling the treatment wheel; a housing
surrounding the treatment wheel; and a plurality of rollers
disposed in the housing in rolling engagement with the track.
In another aspect, the invention is a rotatably supported
regenerative fluid treatment wheel assembly comprising: a
regenerative fluid treatment wheel having a core porous in an axial
direction; a pair of seal flanges extending at least generally
outwardly from the treatment wheel around the outer circumference
of the treatment wheel proximal each of two major opposing axial
faces of the wheel; a housing surrounding the air treatment wheel,
the housing including a pair of opposing outer walls with openings
therethrough at least generally axially aligned with the core of
the treatment wheel; and flexible seals releasably clipped on the
housing surrounding each opening, each seal positioned to contact
one of the seal flanges of the treatment wheel.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed
description of the preferred embodiment of the invention, will be
better understood when read in conjunction with the appended
drawings. For the purpose of illustrating the invention, there is
shown in the drawing an embodiment which is presently preferred. It
should be understood, however, that the invention is not limited to
the precise arrangements and instrumentalities shown. In the
drawings:
FIG. 1 is a schematic view of an open-cycle air conditioning system
utilizing rotatably supported, regenerative fluid treatment wheel
assemblies in accordance with the present invention;
FIG. 2 is a greatly enlarged cross-sectional view of a core of a
regenerative fluid treatment wheel used in the system shown in FIG.
1;
FIG. 3 is an enlarged front elevational view of the regenerative
fluid treatment wheel assembly;
FIG. 4 is an enlarged cross-sectional view of the regenerative
fluid treatment wheel assembly shown in FIG. 3 taken along lines
4--4 of FIG. 3;
FIG. 5 is an enlarged cross-sectional view of the regenerative
fluid treatment wheel assembly shown in FIG. 3 taken along lines
5--5 of FIG. 3;
FIG. 6 is a side elevation of a pivotally supported roller of the
regenerative fluid treatment wheel assembly;
FIG. 7 is a cross-sectional elevation of a clip secured flexible
seal;
FIG. 8 is a schematic perspective view of a drive sub-assembly of
the regenerative fluid treatment wheel assembly;
FIG. 9 is a schematic, partially exploded view of an alternate
regenerative fluid treatment wheel construction;
FIGS. 10 and 11 are cross-sectional view of alternate rim
profiles;
FIG. 12 is a cross-sectional elevation of another roller
embodiment;
FIG. 13 is a partially cross-sectional elevation of an alternate
dual roller embodiment; and
FIG. 14 is a perspective of an alternate spring biased roller
embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Certain terminology is used in the following description for
convenience only and is not limiting.
Turning now to the drawings, FIG. 1 illustrates schematically of a
basic open-cycle air-conditioning system in which rotatably
supported regenerative fluid treatment wheel assemblies of the
present invention may be utilized. A moisture transfer wheel
assembly 11 constitutes the exterior or outside element of the
system. The assembly 11 is separated into two sections so as to
provide an intake path and an exhaust path through the assembly 11,
as indicated by the arrows. A heat exchanger wheel assembly 13,
also partitioned so as to provide intake and exhaust paths is
located substantially adjacent to the moisture transfer wheel
assembly 11, separated only by a solar heat regeneration coil 19.
Auxiliary solar heating coil 21 may be placed in the system for use
in cold months when it is desirable to heat the interior of the
area rather than to cool it. The solar coils include fluid pipes
which are interconnected with standard solar heating units (not
shown). The basic unit terminates in a pair of evaporator elements
15 and 17 separated by a partition 6 with the arrows indicating the
intake air into the building and the air exhausting therefrom. A
supply blower 23 and a exhaust blower 25 are provided so as to
implement the necessary air movement within the system. This
particular open-cycle air conditioner system is disclosed in U.S.
Pat. No. 4,594,860, the entire disclosure of which is hereby
incorporated herein by reference. Accordingly, further description
of the structure of the open-cycle air conditioner system is
omitted for purposes of brevity only and is not limiting.
As is well known, this type of system provides removal of the
moisture from the intake air by the moisture transfer wheel
assembly 11. When moisture is removed from the air, the temperature
of the air increases. The air is subsequently cooled upon passing
through heat exchanger wheel assembly 13, which lowers the
temperature of the warm dry air. Evaporator element 15 adds
moisture to the air, thus reducing the temperature further and
supplying cool air to the conditioned area. The exhaust air passes
through evaporator element 17 and through heat exchanger wheel
assembly 13 so as to remove heat from the heat exchanger and raise
the temperature of the exhaust air. The temperature of the exhaust
air is further raised by means of the solar heating element 19 so
as to provide high temperature air in the exhaust path resulting in
regeneration of the moisture transfer wheel assembly 11. The air
from the moisture transfer wheel assembly 11 is exhausted into the
atmosphere.
FIG. 3 illustrates the construction of a generic regenerative fluid
treatment wheel assembly 30 of the present invention, which
comprises a regenerative fluid treatment wheel 32 and a housing 38.
As is illustrated in FIGS. 4 and 5, the wheel 32 comprises a core
10 and a rim 34. Referring to FIG. 2, the core 10 is porous in an
axial direction and comprised of a plurality of adjoining parallel
channels 14, which extend axially through the core 10. According to
a preferred embodiment of the core 10, each of the channels 14 is
generally in the form of a hexagon in cross section and includes an
internal surface area 16. It is also preferred that the channels 14
be formed from a plurality of stacked layers of material 12. The
layers of material 12 of the channels 14 have a minimum thickness
to inhibit the effect of the wall thickness increasing the pressure
drop through the core 10 and yet provide the core 10 with
sufficient structural integrity to be self supporting. It is
understood by those skilled in the art that the exact thickness of
the walls formed by the layers of material 12 could vary, depending
upon the particular application of the core 10 and existing
manufacturing techniques, without departing from the spirit and
scope of the invention.
Each of the channels 14 includes a centrally disposed longitudinal
axis 18. The channels 14 are preferably sized such that a distance
between and along longitudinal axes of adjacent channels is
generally uniform (i.e., the adjacent channels 14 are equidistantly
spaced from each other and extend generally parallel with respect
to each other). It is preferred that channels 14 of the present
invention, due to their hexagonal cross-sectional configuration, be
closely adjoined to increase the available transfer surface per
unit of volume.
The use of channels having a cross section which is generally in
the form of a hexagon is advantageous over other geometries,
including, but not limited to sinusoidal, square, and triangular.
The theoretical available transfer surface area (i.e., based upon
standard measurements and calculations of the geometries prior to
coating the interactive material) of a hexagon is greater than the
transfer surface area of a sinusoidal, triangle or square for a
given volume.
While in the present invention it is preferred that the channels 14
be configured to be generally in the form of a hexagon in cross
section, it is understood by those skilled in the art that the
cross section of the channels could be other straight-sided shapes
with equal angles and equal side lengths, such that the cross
section approaches a circle, and which permit the channels to be
closely adjoined to maximize the greatest transfer surface area per
unit volume without departing from the spirit and scope of the
invention. Although it is also understood by those skilled in the
art that other geometries could be used, such as, triangle, square,
sinusoidal, so long as the operating parameters described below are
attained, without departing from the scope and spirit of the
invention.
Referring back to FIGS. 3 through 5, there is shown a first
preferred embodiment regenerative treatment wheel assembly of the
present invention indicated generally at 30, which by suitable
selection of the core 10, might be either a moisture treatment
wheel assembly 11, heat exchanger wheel assembly 13 or any of a
variety of other known types of regenerative wheels.
For smaller regenerative wheels, the layers of material 12 which
form the channels 14 of the core 10 can provide the core 10 with
sufficient structural integrity to avoid the requirement of a hub
assembly and spokes. Thus, in the preferred embodiment 30 shown in
FIG. 3, there is no hub spokes in the transfer wheel 32.
A track 36 of any configuration is provided on the transfer wheel
32, encircling the wheel 32 along its outer circumference.
Preferably the track 36 is integral with the rim 34 and is formed
in one piece with the rim, by extrusion or molding, for example.
The track 36 is defined by a pair of mirror image flanges, which
extend generally radially outwardly from the external surface of
the rim to define a channel, which is preferably centered axially
on the rim. The track 36 allows the wheel 32 to be supported at its
periphery and rotatably mounted within the housing 38, as shown in
FIG. 3. The housing 38 is generally in the form of a parallelepiped
and includes a pair of major opposing sides 40 with a pair of
semi-circular openings 40a and 40b on each side 40 to divide the
fluid flows passed through the wheel 32. This allows the wheel 32
to be placed in a desiccant air-conditioning system of the type
described in U.S. Pat. No. 4,594,860, incorporated by reference
herein in its entirety.
A plurality of rollers or "support wheels" 42 are disposed within
the housing 38 in rolling engagement with the track 36. The support
wheels 42 are positioned to rotatably support the wheel 32 in the
housing 38 such that the core 10 of the wheel 32 is in alignment or
registry with the semicircular openings 40a and 40b. Desirably, at
least three and, preferably, at least four support wheels 42, 44
are provided. In the embodiment shown, two of the wheels 42 are
located relatively closely together near the bottom of the
regenerative wheel 32 and equally support its weight. The remaining
two wheels 42 are preferably located equidistant from one another
and from the closer of the bottom two support wheels 42 to fully
surround the transfer wheel 32 and thereby locate the wheel 32 both
axially and radially within the assembly 30. As a result of this
rim located axial support, the regenerative wheel no longer needs
to be flat and true. It now merely needs to be flat. Three of the
support wheels 42 are supported within the housing 38 as shown in
FIG. 5 by a generally T-shaped support member 44, which rotatably
supports the support wheel 42. One of the four support wheels 42,
preferably one of the two upper wheels, is supported for movement
towards and away from the track 36. Instead of being fixedly
coupled to the housing 38, the support member 44 of the fourth
wheel is preferably mounted on a plate 46 coupled at one end by a
hinge 48 or other pivotal coupling to a mounting plate 49 coupled
with the housing 38 as shown in FIG. 6. A bias member 50,
preferably in the form of a coil spring, is coupled with that one
support wheel 42 and the housing 38 so as to bias that one support
wheel 42 towards the track 36. The force provided by the bias
member 50 is designed to be sufficient to overcome any defection
caused by the seals, air or other displacive forces. This one
movable, biased support wheel is significant to the invention in
that it adjusts and compensates for eccentricities in the
regenerative transfer wheel 32.
The plurality of support wheels 42 are preferably also located in a
single plane passing through the center of the regenerative wheel
32 perpendicular to its central axis to uniformly distribute the
weight of the regenerative wheel on the support wheels 32. It is
appreciated that the present invention allows the regenerative
wheel 32 to be located completely in the axial and radial
directions without the use of a center hub or seals for alignment.
It should further be appreciated that the support wheels 42 further
allow for the easy and insertion and removal of the regenerative
wheel 32 for seal maintenance as well as allowing the seal force to
be significantly lower. The regenerative wheel 32 is further
preferably provided with a pair of mirror image seal flanges 52,
which extend outwardly, preferably radially, from the regenerative
treatment wheel 32 around the circumference of that wheel 32,
proximal each of the two major opposing axial faces of that wheel
32. Preferably the seal flanges 52 are integral with the rim 34 and
formed in one piece with the rim 34 and the track 36.
As can be seen in FIG. 5 flexible seals 54 are mounted on the
housing 38 surrounding each of the semicircular openings 40a, 40b.
Seals 54 are positioned to contact the seal flanges 52 of the
treatment wheel 32 as shown in FIGS. 4 and 5, substantially and
preferably at least essentially entirely around the treatment wheel
thereby preventing fluid flow losses. Preferably, each of the seals
54 is releasably clipped to an edge of one of the pair of opposing
outer walls 40, which define each of the openings 40a, 40b.
A currently preferred flexible seal configuration is depicted in
cross-section in FIG. 7. The preferred seal 54 includes a generally
bulbous, hollow portion 54a integral with a more resiliently
flexible clip portion 54b. The clip portion 54b preferably includes
a more resilient "C" channel member 154, which defines an open
channel 154'. The elastomer 155 of portion 54a and the channel
member 154 are preferably joined together by a flexible polymeric
plastic 156, which surrounds the channel member 154 and defines a
plurality of flexible engagement fingers 157, which extend into
channel member 154. The configuration of the clip portion 54b
allows that portion to be releasably clipped directly to an edge of
the outer wall in phantom 40 defining either of the openings 40a,
40b. If desired, additional means such as a releasably pressure
sensitive adhesive may be provided to more securely yet still
releasably clip the seal 54 to the outer wall 40. Alternatively, a
seal without a clip could be secured directly to the outer wall 40
with a suitable epoxy or pressure sensitive adhesive. The seals 54
may be molded in a "D" shape or could be provided as a continuous
member which is extended around and cut to fit about each opening
40a, 40b.
The extreme distal end of the bulbus portion 54a of each seal 54,
which extends around the curved portion of the opening 40a, 40b,
contacts one of the seal flanges 52 of the regenerative transfer
wheel 32. The portion of the seal 54, which extends diametrically
across the wheel 32, defines the air partition between adjoining
halves of the wheel 32 and contacts the exposed end surface of the
core 10. Preferably, a wear tape 58 is applied to the extreme
distal end of the bulbus portion 54a of each seal 54 to prevent
excessive wear of the seal and protect the underlying elastomer.
The wear tape 58 may be affixed to the seal 54 by various means,
preferably a layer of an appropriately selected adhesive 60.
The above described clip mounted seals 54 save manufacturing and
repair costs as the seals 54 can be more quickly installed and
removed than could prior seals, which were fixedly secured to the
housing by removable fasteners such as screws or nuts and
bolts.
A drive mechanism is provided as part of the assembly and drivingly
engages the exterior of the rim 34 to rotate the wheel 32 with
respect to the housing 38. The major components of the drive
mechanism are depicted schematically in FIG. 8 and indicated
generally at 70. Drive mechanism 70 includes a flexible member 72,
preferably a belt, which encircles the regenerative treatment wheel
32 in driving engagement with the wheel 32, specifically the rim 34
of the wheel. Drive mechanism 70 further include a drive member 74
within the housing 38 in driving engagement with the flexible
member 72 and a prime mover 76 in driving engagement with the drive
member 74. Preferably the prime mover 76 is a flange mounted
electric motor having a drive shaft 78, which is rotationally
engaged with the drive member 74. The drive member 74 is preferably
a pulley. Preferably an idler pulley 80 also is provided on an arm
82 rotatably mounted to a post 84 extending from a mounting plate
86. Preferably, the prime mover 76 is flange mounted to the outer
side of the mounting plate 86 with the drive shaft 78 extending
through the mounting plate 86 into driving engagement with the
drive member 74. The mounting plate 86 fits over an opening
provided through one of the two major opposing outer walls 40 to
one side of the wheel 32 and is removably secured to that wall 40
by conventional means such as screws or bolts. This construction
permits the easy removal and installation of the entire drive
mechanism 70, apart from the flexible member 72, as a sub-assembly
for simplified construction, ease of maintenance and repair and
ease of sealing of the housing 38, on which the drive mechanism is
mounted. In the past when motors were required that were larger in
size then could be accommodated within the housing, a sub-housing
was built around such motor where it was mounted to the housing or
through the housing. The present invention permits the use of a
plate, which is easily installed and sealed along its four sides,
in place of the more detailed construction of an entire,
multi-sided sub-housing. The motor 76 is conventionally supplied
with an internal shaft seal which prevents fluid leakage through
the motor. Sealing the motor to the plate around the flange
completes the assembly seal at the drive mechanism.
Fabrication of the core is described in detail in related U.S.
patent application Ser. No. 08/246,548, filed May 20, 1994
incorporated by reference therein. As an example of the invention,
it is preferred that the layers of material 12 for a moisture
transfer wheel 11 or heat transfer wheel 13 be comprised of a
non-metallic, high-strength, temperature-resistant, low thermal
conductivity material, such as Nomex.RTM. aramid in paper form. The
process of assembling the layers of material 12 in the form of the
channels 14 is well understood by those skilled in the art. Where
the regenerative wheel assembly 30 is used to dehumidify air,
Aeroweb.RTM. HMX-20 aramid honeycomb without resilient resin
coating, manufactured by CIBA Composites of Anaheim, Calif.,
division of CIBA Geigy Corp. of Ardsley, N.Y. may be used as the
material of the walls 12, which are preferably coated with a
crystalline titanium silicate molecular sieve zeolite compound
manufactured by Engelhard Corp. of Edison, N.J. under the name ETS
and disclosed in U.S. Pat. No. 4,853,202, which is hereby
incorporated by reference. Uncoated Aeroweb.RTM. HMX-20 is also
preferred for the core where the wheel is used for heat transfer in
a desiccant air conditioning system. However, it is understood by
those skilled in the art that the layers of material 12 and the
manner in which they are formed are not pertinent to the present
invention, and that other materials, such as kraft paper, nylon
fiber paper, mineral fiber paper and the like could be used to
construct the layers of material 12 and that other methods could be
used to form the hexagonal channels 14, such as extrusion,
machining or molding, without departing from the spirit and scope
of the invention.
It is preferred that the thickness also the core be formed from
stacked layers 12 of the Aeroweb.RTM. material, each having a
thickness of about 0.0015", although the thickness of the walls
formed by joined layers of material could be in the range of about
0.001 to 0.006". It is further preferred that the spacing between
immediately adjoining pairs of longitudinal axes 18 of the channels
14 in the range of about 0.050 to 0.125".
To form a wheel 32, a circle is trimmed from a piece of core
material, which is larger than the diameter of the wheel, using a
cutting device such as a band saw, after what will be the center of
the core is rotatably mounted on a support adjoining the saw. The
present invention is not limited to the use of the preferred
Aeroweb.RTM. or other aramid material.
Other materials such as Kraft paper, nylon fiber paper, mineral
fiber paper and the like could be used to construct the core of the
wheel used for moisture transfer of heat exchange. Again, still
other materials could be used.
Preferably, the rim 34 is formed from an extrusion including, with
the material defining the rim, the projections defining the track
36 and the seal flanges 52, in one straight piece. The straight
piece is preferably cut to size, bent to form a circle and welded
or otherwise mechanically fastened to itself. Automotive wheel
turning equipment might be used to bend the extrusion. The
preferred core 10 is preferably secured to the rim 34 by the use of
adhesive, such as a conventional epoxy like Mavidon MF2000 A and B
or possibly a foaming epoxy. Foaming epoxy is preferred as it will
conform during curing to eccentricities which are present between
the core and rim. However, the rim 34 could secure the core 10
solely by means of an interference or friction fit.
While aluminum is preferred for its high strength, light weight and
ease of fabrication, other materials such as steel or polymeric
materials could be used to construct the rim and might be necessary
or desirable for other types of wheel uses and other types of core
materials. Extrusion permits the rim and the various projections
forming the track, sealing flange and any core engaging element(s)
(if the rim is mechanically or frictionally secured with the core)
to be formed in one piece in one step. Aluminum extrusion results
in tighter rim and seal flange width tolerances than could be
attained using traditional machining techniques, as well as
providing a smooth exterior surface to the seal flange, which
permits the flexible air seals 54 to be run along the flanges. In
addition to extrusion, one piece rims with multiple projections can
also be formed directly by casting or molding and can be formed in
segments which are joined or one-piece. Though less desirable, the
track and seal flanges could be added to a flat sheet stock
mechanically or adhesively or the desired rim profile machined from
conventional bar stock.
While the extrusion process provides seal flanges 52, which are
sufficiently smooth to directly contact the seals, the seal flanges
52 could also be coated with even lower friction material(s) such
as low friction graphite, Teflon.RTM. or molybdenum disulfide to
further reduce the wear of the mechanical seals. These and other
materials could can be applied by any of several different methods
including painting, dipping or powder impregnation.
The opposing faces of the core 10 may be coated with an epoxy or a
low viscosity casting compound to increase the durability of the
exposed surface against damage as well as to further mechanically
strengthen the core 10.
The bulbous portion 54a of the flexible seal 54 may be extruded
from an elastomer 155 such as, for example, an EPDM (ethylene,
propylene, diene monomers), silicone, neoprene, or urethane rubber
and co-extruded with a plastic or metal channel member 154 and a
flexible, polymer plastic material 158 or a natural or synthetic
rubber in dip portion 54b. Alternatively, such portions 54a/54b can
be separately made and subsequently assembled in a conventional
fashion with an appropriate adhesive. Such seals can be obtained
from various commercial suppliers as a stock automotive trim item.
Part No. 75001616 of Standard Products Inc., Dearborn, Mich., can
be used. This item is normally used as a static trim seal in
automobiles. For the curved portions of the seals 54 which contact
the seal flanges 52 of the regenerative wheel 32, the wear tape 58
is preferably a Furon Dixon Rulon XL tape with a pressure sensitive
adhesive (3M stock number 9485-PC). For the portions of the seals
54 which extend diametrically across the face of the core 10, a
Furon Dixon Rulon F tape with the same pressure sensitive adhesive
can be used. An epoxy such as Mavidon 5110 A and B can be used if
greater holding strength is desired with either tape. Also, this
method of sealing may be used with other types of regenerative
wheels including conventional hub supported and located wheels. The
tapes are supplied in rolls with the pressure sensitive adhesive
and are directly applied to the exposed bulbous portion 54a of each
flexible seal 54. The pressure sensitive adhesive allows the tapes
to be easily applied and securely held thereby reducing
manufacturing costs, while enhancing the elastomeric
characteristics of this seal as the bulbus portion 54a can be fully
made of elastomer and need not be fully covered with the wear
strip.
The flexible member 72 is preferably a timing belt having a toothed
interior surface (not depicted) and the drive member 74 has a
toothed exterior surface (also not depicted) engaging the teeth of
the belt. Due to the more extensive surface of the wheel rim 34
contacted by the flexible member 72, it is not necessary to provide
teeth on the wheel. However, teeth could be provided, if desired,
and could be added to an extrusion by mechanical and/or adhesive
fastening. In addition to belts, other types of flexible members
may be used, depending upon a particular configuration of the
assembly 30, including, but not limited to chain, elastic bands,
V-belts, rubber coated cabling, etc. It is presently preferred to
run the flexible member over the rim 34 between the track 36 and
one of the two seal flanges 52 to avoid any interference with any
of the support wheels 42. However, it would be possible and, in
certain instances, perhaps desirable to run the flexible member 72
in the track 36.
The housing 38 may be made in a conventional fashion employing
simply sheet metal panels with or without structural steel as
needed. Preferably, the housing 38 is symmetric with respect to a
vertical plane through the center of the regenerative wheel 32 such
that pairs of identical panel members may be joined to one another
and/or an internal frame to form each of the two major outer
opposing walls 40 of the housing 38.
The present invention is most advantageously employed with
regenerative fluid treatment wheels employing core material which
are self-supporting for the size of the wheel fabricated. However,
other advantages of the present invention can be achieved by its
application to hub and spoke wheels as well. FIG. 9 depicts a
partially exploded, regenerative fluid treatment wheel 132 having a
rim 134 with a track 136 encircling the wheel 132 on the rim 134.
Seal flanges 138 are provided projecting radially outwardly along
the lateral circumferential edges of the rim 134. A hub assembly
140 is provided at the center of the wheel 132. A plurality of
identical spokes 142 extend radially between the hub 140 and the
rim 134. The spokes 142 are fixedly secured between adjoining
segments 134a/134b and 134a/134d of the rim, for example by nut and
bolt fasteners (not depicted) while an opposing end of each spoke
142 is received in an appropriate slot in the hub assembly or
simply "hub" 140. The core of the wheel is provided by a plurality
of substantially identical annular segments, two quarter-circle
segments 110a and 110b being shown already installed and a third
segment 110c being shown in a partially exploded view before
installation. The core segments 110a-110c can be secured in the
wheel 132 against movement in the axial direction in a variety of
ways including adhesives, as indicated previously, and interference
engagement as is illustrated by wheel 132. Each of the spokes 142
is provided with protruding, radially extending flanges 144 on
either side of the spoke, which engage with slots or grooves cut
into the long straight sides of each core segment 110a-110c, two
grooves 112 of the segment 110c being shown in phantom. When the
segment 110c is installed between the adjoining pair of spokes 142,
each of the flanges 144 from the pair of adjoining spokes will
project into engagement with the slots 112 provided on the opposing
side of the core segment 110c. The core segment 110a-110c may be
simply mechanically joined in this way to the spokes and rim or be
further adhered, if desired, to further retain the core
segments.
Preferably, the hub 140 is of a symmetric polygon configuration, a
square configuration being depicted. This greatly simplifies
cutting the small side wall of the core segments 110a-110c, which
directly faces the hub and avoids the necessity of making a small
radius cut along that portion of the core segment. Alternatively, a
single elongated roller bearing (not depicted) might be provided
within the hub 140, extending substantial the axial length of the
hub 140, to rotatably support the wheel 132 on a fixed axle (not
depicted) extended through the central axial opening shown in the
hub assembly/40. The provision of surrounding support wheels (not
depicted) engaged with the track 136 will eliminate the axial load
on the hub bearing. It further eliminates the need to manufacture
the regenerative wheel 132 with a precisely true center hole for
the shaft as the single bearing will have some slop and tolerance
and eccentricities will be accommodated by the biased support
wheel.
Preferably, the core sections 110a-110c and the like would be cut
from the preformed Aeroweb.RTM. honeycomb sheet of the type
previously noted. Initially, long straight sides of the core
material would be cut forming a pie-shaped wedge. The wedge would
preferably be mounted in a pie-shaped rotating jig for a major
radius cut. The pointed end of the wedge would be removed with a
straight transverse cut before or after the radius cut. Slots may
be cut at any time in the long straight sides of each core segment
110a-110c.
FIG. 10 shows a cross section of a different rim embodiment 234
having a track 236 and sealing flanges 238, which is suitable for
extrusion or molding. The extreme distal ends of the seal flanges
238 are inwardly tapered to their tips. This eases installation and
removal of the wheel and minimizes damage to the flexible seals,
which are positioned to contact the straight sides of the seal
flanges radially inward of the taper. FIG. 11 shows a cross section
of yet another rim 334 with integral track 336 and seal flanges
338, having a geometry particularly suitable for fabrication by
conventional sheet metal bending technologies, for example in
galvanized or stainless steel.
FIG. 12 discloses yet another roller embodiment 242 in which the
bearing portion 243 of the wheel is supported on a hollow tube
portion 244 that is rotatably supported on bearings 245 on an axle
246 extending between the major opposing outer walls 40 of a
housing 38.
FIG. 13 shows a dual support wheel design in which a pair of wheels
342 are rotatably supported on a pair of axles 346 each of which is
supported at one end by a suitably configured mounting plate 348,
which again could be coupled to or form part of a frame of a
housing 38.
FIG. 14 shows an alternative spring loaded roller construction in
which a support wheel 442 is mounted by means of a yoke 444 having
a hollow base 445 mounted to pivot in an axle 446 provided on a
mounting plate 447 which may be attached to or used as a portion of
the frame of the housing. A torsional spring (not depicted) within
the hollow base reacts with the axle 446 and/or mounting plate 447
to bias the wheel 442 against a regenerative fluid treatment
wheel.
It will be appreciated by those skilled in the art that changes
could be made to the embodiments described above without departing
from the broad inventive concept thereof. It is understood,
therefore, that this invention is not limited to the particular
embodiments disclosed, but it is intended to cover modifications
within the spirit and scope of the present invention as defined by
the appended claims.
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